databases/py-ormar: add port: Simple async ORM with fastapi in mind and pydantic validation

The ormar package is an async mini ORM for Python, with support for Postgres,
MySQL, and SQLite.

The main benefit of using ormar are:

• getting an async ORM that can be used with async frameworks (fastapi, starlette etc.)
• getting just one model to maintain - you don't have to maintain pydantic and other orm model (sqlalchemy, peewee, gino etc.)

The goal was to create a simple ORM that can be used directly (as request and
response models) with fastapi that bases it's data validation on pydantic.

WWW: https://github.com/collerek/ormar

PR: 257370
Reported by: Goran Mekić <meka@tilda.center> (new maintainer)
Reviewed by: koobs